No oil in left side cam oil line...

MichiganMat · MichiganMat's Garage

Just finished my rebuild and Im not getting any oil at all in the left side cam hose. My gauge in the dash says that Im getting good pressure to the right side, and loosening the fittings on that hose shows lots of oil in the line. I can't for the life of me figure out why the left side would be dry though. Any thoughts?

Im trying to find the routing pictures for how oil is routed to that outlet in the case but I honestly can't find it.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by MichiganMat

Just finished my rebuild and Im not getting any oil at all in the left side cam hose. My gauge in the dash says that Im getting good pressure to the right side, and loosening the fittings on that hose shows lots of oil in the line. I can't for the life of me figure out why the left side would be dry though. Any thoughts?

Im trying to find the routing pictures for how oil is routed to that outlet in the case but I honestly can't find it.

MM,

Test if oil is coming out from the supply point. Remove the ignition distributor and oil line connected to the crankcase for the left side (cylinder 1-2-3). Disable the FP and ignition. Crank the engine using the starter and look closely if oil is spewing out from the fitting. Place some rugs by the fitting just in case it started spraying oil (?). If oil is not coming while cranking the engine, there is blockage or restriction in the oil passage (crankcase).

Tony

Walt Fricke · 06-26-2017, 05:01 PM

Mat - did you by chance pull the oil line plugs to do a thorough clean of the oil passages, and then thread the holes and insert plugs?

When you do that you have to get clever about how far in you screw the plug which is up where the two cam lines diverge, and how you groove the plug, and how you screw it in so the groove helps admit oil to a passageway.

Of course, my memory may be faulty as to just which oil passage - right or left - is affected.

And if you didn't pull the plugs, the theory is not valid. However, since this is big trouble you might consider pulling that plug.

I assume that cranking the motor (not starting it, of course) won't cause oil to show up at the fitting out on the cam carrier? That would rule out an obstruction in that banjo or the spray bar and so on out there. Then remove the line entirely, to rule out the line - steel, rubber, and the T fitting for the Carrera tensioners - as the source of the blockage. After that it has to be something in a short section of the case - remove the fitting and put a borescope up there - you can buy a USB one thin enough for maybe $10 to plug into a tablet or laptop.

trond · trond's Garage

Walt; your comment about possibly blocking oil supply to the spray bars made me worried. I did install NPT plugs on forwards end of the cam housings, and I am about to fire up the rebuilt engine. Is it possible that oil supply could be impaired by the NPT plugs? I did not think it would be any risk as the oil lines come in at the opposite end of the spray bar... ?

Flat6pac · 06-27-2017, 10:58 AM

Trond, the plugs you replaced had a point on them used to locate the proper location of the spray bar.
Bruce

trond · trond's Garage

oh no ! Maybe this can explain the wear issues I had on rockers and cams. How to deal with this ?

However the top blind plugs (17 mm wrench on the opposite end of the oil supply fitting and banjo, part no 901 105 374 00) have a pin that locate the bars.

Also re-reading Walts post it does not seem to refer to the spray bars so false alarm I think. Nerves on end after weeks of wrenching and pouring all I got into the build....

Walt Fricke · 06-28-2017, 10:00 PM

The oil line plug you need to be especially careful about if you thread and use NPT plugs is on the right side case half, near where the oil temp and pressure senders are.

Using a threaded plug for the spray bar ends is straightforward.

Mat has a mystery - no oil to the left side cam housing, hence wondering how to chase the location of a blockage down.

Uwon · Uwon's Garage

MM,
I just went thru a similar issue. Here is the thread in case you have not seen it.
Cam removal question
Hope this helps.
Johan

Walt Fricke · 07-03-2017, 04:07 PM

If one of my race motors had a left side cam oiling problem, and oil was not coming out the fitting on the left side of the case, I would definitely suspect I had messed up with threading a plug into the end of the main oil gallery. I just checked a case I have apart, and the left side passage which is at 90 degrees to the fore and aft main gallery is the one which is very close to the plug you can see sort of up above the oil temp sender. To get enough thread engagement you pretty much have to cut a groove in the back of your brass plug, and "clock" the plug so the groove directs oil to the left side cam oiling passage.

I suppose replacing the factory press fit plug but getting it in too deep might cause the same kind of issue, or someone making one but not being careful to keep it no longer than factory could cause a problem.

But if the engine here did not have the oil gallery end plug out as part of overall cleaning during a split case rebuild, this doesn't seem a likely cause of a somewhat mysterious issue - as far as we are told.